Related papers: Rapid AGN accretion from counter-rotating discs
In many black hole systems, the accretion disk is expected to be misaligned with respect to the black hole spin axis. If the scale height of the disk is much smaller than the misalignment angle, the spin of the black hole can tear the disk…
The dynamics of galactic nuclei reflects the presence of supermassive black holes (SBHs) in many ways. Single SBHs act as sinks, destroying a mass in stars equal to their own mass in roughly one relaxation time and forcing nuclei to expand.…
Several processes may limit the accretion rate onto a super-massive black hole (SMBH). Two processes that are commonly considered (e.g., for sub-grid prescriptions) are Bondi-Hoyle-Lyttleton accretion and the Eddington limit. A third one is…
Simulations of binary black hole mergers indicate that asymmetrical gravitational wave (GW) emission can cause black holes to recoil at speeds up to thousands of km/s. These GW recoil events can dramatically affect the coevolution of…
We have used high-resolution zoom-in simulations of direct collapse to supermassive black hole (SMBH) seeds within dark mater (DM) halos in the presence of magnetic fields generated during the collapse, down to $10^{-5}$ pc or 2 AU. We…
We investigate how AGN disk turbulence affects the orbital dynamics of a stellar-mass black hole (BH) initially located at a migration trap, focusing on the long-term behavior of eccentricity and inclination in the quasi-embedded regime. We…
The cosmic history of supermassive black hole (SMBH) growth is important for understanding galaxy evolution, reionization and the physics of accretion. Recent NuSTAR, Swift-BAT and \textit{Chandra} hard X-ray surveys have provided new…
Supermassive black hole (SMBH) binaries in gaseous and stellar environments are prime targets for next-generation space-based gravitational wave detectors. Yet, realistic accretion conditions under which these binary systems evolve are not…
Here we propose a mechanism for efficiently growing intermediate mass black holes (IMBH) in disks around supermassive black holes. Stellar mass objects can efficiently agglomerate when facilitated by the gas disk. Stars, compact objects and…
Measuring the spins of supermassive black holes (SMBHs) in active galactic nuclei (AGN) can inform us about the relative role of gas accretion vs. mergers in recent epochs of the life of the host galaxy and its AGN. Recent advances in…
Accreting black holes (BHs) produce intense radiation and powerful relativistic jets, which are affected by the BH's spin magnitude and direction. While thin disks might align with the BH spin axis via the Bardeen-Petterson effect, this…
Accretion discs around black holes in X-ray binary stars are warped if the spin axis of the black hole is not perpendicular to the binary orbital plane. They can also become eccentric through an instability involving a resonance with the…
Binary black hole (BBH) mergers are the primary sources of gravitational wave (GW) events detected by LIGO/Virgo. Binary black holes embedded in the accretion discs of active galactic nuclei (AGN) are possible candidates for such GW events.…
In the $\Lambda$CDM scenario, small galaxies merge to produce larger entities. Since supermassive black holes (SMBHs) are found in galaxies of all sizes, SMBH binaries (SMBHBs) are generally expected to form during the amalgamation of…
Merging supermassive black hole (SMBH) binaries will likely be surrounded by a circumbinary accretion disk. Close to merger, gravitational radiation-driven inspiral will happen on timescales faster than the effective viscous time at the…
In this paper we report on the formation of magnetically-levitating accretion disks around supermassive black holes. The structure of these disks is calculated by numerically modelling tidal disruption of magnetized interstellar gas clouds.…
It is well established that cosmic supermassive black hole (SMBH) growth peaks at $z\approx1.5-2$, followed by a strong decline of $\approx1-1.5\,\rm dex$ toward the present day, with the comoving number density of higher-luminosity active…
Understanding how supermassive black holes (SMBHs) pair and merge helps to inform predictions of off-center, dual, and binary AGN, and provides key insights into how SMBHs grow and co-evolve with their galaxy hosts. As the loudest known…
Keplerian accretion discs around massive black holes (MBHs) are gravitationally unstable beyond a few hundredths of parsec and should collapse to form stars. Indeed an accretion/star formation episode took place a few millions years ago in…
We present the black hole mass--bulge velocity dispersion relation for a complete sample of 75 soft X-ray selected AGNs. We find that the AGNs with highest accretion rates relative to Eddington lie below the \mbh--\sig\ relation of broad…